Fireproof Endless Type Round Sling

A fireproof endless type round sling is a closed loop of high-tenacity filament inside a flame-retardant woven sleeve, built so that it resists ignition, stops burning when the flame or spark source is removed, and does not drip molten polymer onto the load or the floor. The endless form matters in hot work: there is no eye, no thimble and no stitching in the load path, so the whole circumference can be turned to face the hazard and the bearing point can be moved instead of retired. The RK01 series on this page runs from 1 ر ل 20 t in eleven steps, 1.5 م ل 80 م, in FR polyester or para-aramid.

1. ماذا “fireproof” means on a sling, وما لا يفعل ذلك

Three different claims get sold as fireproof, and only the first two are properties of the sling. The third is a property of the test.

It does not sustain combustion. Once the ignition source leaves, the material stops burning. That is what a limiting oxygen index above 28 buys you: the fibre needs more oxygen than the air around it contains to keep a flame going. Ordinary polyester sits near 20-21 and will keep burning in air.

It does not melt and drip. Polyester softens and melts around 250-260 درجة مئوية; aramid has no melting point and chars instead. A burning drip is worse than a flame in a workshop, because it lands on whatever is underneath and it takes the sling’s strength with it.

It is not a fire barrier. No textile sling is rated like a fire door. “Fireproof” here means it will survive the sparks, slag and spatter of hot work and can be pulled out of a brief flame, not that it can be left in a fire, used as a heat shield, or immersed in molten metal. Those are different products and different tests.

2. بناء: where the fire protection sits

The load path is a parallel bundle of filament running the full circumference inside a woven tube. The sleeve carries no load. It takes the abrasion, the sparks, the slag and the sunlight — and on a fireproof build it is also where most of the flame protection is put, because the sleeve is the part that meets the hazard and the part that can be replaced.

That gives three practical builds:

Two details decide how a fireproof sling behaves in service, and neither is visible in a photograph. The first is sleeve fit: a sleeve that can slide lets you move the burnt patch away from the bearing line and keep working, while a tight sleeve concentrates every spark in the same place. The second is where the sleeve is doubled. On the RK01 sizes above 10 t the sleeve is normally doubled over the length that will bear on the load, because that is where contact pressure and heat arrive together.

3. Fire performance: the figures to ask for

Fire performance on a textile sling is a set of measured behaviours, not a single badge. These are the four that decide whether a build is worth the premium, with the test each one comes from and what it means on the shop floor.

Read the LOI row together with the temperature row, because they answer different questions and buyers routinely buy one while needing the other. An FR polyester sling with an LOI of 30 will shrug off a welding spark and then lose strength against a 120 °C billet, and an aramid sling that survives the billet will still be damaged by a sustained flame at the same spot. Neither is “more fireproof” than the other; they fail at different things.

4. المعلمات التقنية: the RK01 series

The dimensional series below is the working table for this product. It gives, for each article number, the vertical working load limit, the approximate body thickness and width, the length range and the unit weight — which is the figure that decides whether the sling can be carried up a ladder and how much a 20 m body weighs on the hook.

Dimensions from the RK01 specification sheet, reproduced unchanged. Weight is quoted per metre of body, لذلك أ 5 ر حبال في 6 m effective length is about 7.2 kg before packing. Capacities above 20 t are built to order on the same construction; ال حبال مستديرة لا نهاية لها شديدة التحمل من الأراميد range runs to 100 ر.

5. Capacity depends on the hitch, not on the sleeve

The figure on the label is the vertical rating of a single leg. Every other arrangement multiplies it, and on a fireproof sling the multiplication is what decides whether you can pick the load with the size you have or need the next one up.

Two points catch most orders. A choker costs a fifth of the capacity, and a choker is exactly what you are forced into when the load has no lifting point and the sling has to grip it. And four legs are calculated on three, because a real load never sits perfectly symmetrical — the factor is 2.1 بدلا من 2.8. Read both before choosing the size, not after the sling arrives. Where the headroom is short and the legs would open past 45°, أ شعاع الرفع keeps the legs vertical and recovers the capacity the angle has just spent.

6. طول: the figure that is a factor of two out

حبال لا نهاية لها ليس لها نهاية, لذلك يمكن نقل طوله بطريقتين, and quoting the wrong one is the most expensive mistake on this product because the sling has to be remade rather than adjusted.

We quote and print the effective length as standard, so the label and the quotation always agree. لسلة, قياس محيط الحمل, add the headroom to the hook and quote that as the effective length — the body then takes the long way round, and the legs stay at the angle the capacity table assumes.

7. Endless type against eye type

Both are sold as fireproof round slings, and the difference is only in the terminations — but the terminations are what decide how the sling wears in hot work.

If the lift repeats from the same hook to the same pick-up points, the eye type is quicker to rig; انظر حبال مستديرة مع عيون يتراوح. If the hazard moves, or the sling has to be re-reeved between lifts, the endless type is the one that survives the week.

8. Where a fireproof endless sling is specified

9. تقتيش, and what ends a fireproof sling’s life

The sleeve is a working part, and on a fireproof sling it is the part that is expected to be damaged. The point of the construction is that you see the damage on the outside before the core is affected.

• Look for scorching and glazing first. لامعة, stiff or brown patch is heat that has already been absorbed. It is telling you how much of the sleeve’s margin has been used.
• Check for a burnt-through patch. A hole that exposes the core is a retirement, not a repair — even if the core looks intact.
• Slide the sleeve back where it will move. On an endless sling you can inspect a working length of core directly; a dull or brownish core has been overheated and no sleeve replacement recovers it.
• تحقق من طول المحمل بالكامل, not the visible side. Sparks land where the sling wraps, which is usually the side facing away from you.
• اقرأ الملصق. If the working load limit, لا يمكن قراءة الطول أو الدفعة, لا يمكن التحقق من القاذفة وتخرج من الخدمة.
• لا تسحب أبدًا حبالًا محملة. Friction builds heat from the outside in, where you cannot see it start.

10. What to send for a quotation

11. الأسئلة المتداولة

12. Why buy fireproof round slings from Lift

We have been making slings, webbing and rope in Taizhou, جيانغسو منذ ذلك الحين 1985, with the core, the sleeve and the stitching under one roof — which is what makes a build-to-order fireproof sling a production order rather than a special project. الأعمال, the test laboratory and the export paperwork are described on the about us صفحة.

• The build is chosen, not guessed. Tell us what the sparks land on and whether the body touches the hot workpiece, and the core and sleeve are paired to that hazard rather than to a catalogue line.
• Spare sleeves. A burnt sleeve is a consumable. Replacement sleeves are supplied separately so a scorched cover does not take a serviceable sling out of the rack.
• Tested and marked per sling. تم تحميل الدليل قبل الإرسال, with the record matched to the serial on the label; a self-testing laboratory with a 1,000 t tensile machine behind the range, مع م, DNV and PICC certification — see شهادة.
• One supplier for the hot job. Fireproof round slings, aramid webbing slings, high temperature webbing slings, حبال حزام و أجهزة الرفع from the same works, so the whole lift is specified against one set of figures.

13. طلب عرض أسعار

Send the load per leg and the hitch, the effective length, what the sling will touch and for how long, and the marking your market requires. سوف نؤكد البناء, the factor and the length the same working day, واقتبس المصنع مباشرة مع الرسم, a proof-load record and a sample sling. Full contact details are on the صفحة الاتصال.

شركة رفع الرافعات, Ltd — Lifute Industrial Park, تايتشو, جيانغسو, الصين
هاتف: +86 523 8693 5818 | واتساب: +86 180 6600 2268

Related reading: حبال مستديرة لا نهاية لها for the general-purpose form, العين العين جولة حبال for the fixed-length alternative, جميع الرافعات المستديرة for the full range, و حبال داينيما المستديرة where weight, not heat, is the constraint.